The invention relates to a method and system for suppressing nuisance alarms of a Floating Production, Storage and Offloading (FPSO) surveillance system due to oscillating liquid level variations in FPSO crude oil and/or other liquid storage tanks resulting from oscillating motions of the FPSO unit during severe weather conditions.
FPSO surveillance systems are available from vendors, such as Moxa Inc. (URL: http://www.moxa.com/application/Alarm-to-Video_Monitoring_for_Offshore_Oil_Gas_FPSO.htm) and may be part of a Distributed Control System (DCS) used for integrated control of FPSO crude oil production, storage, treatment and offloading operations.
FPSO surveillance systems may comprise liquid level monitoring equipment which monitor a liquid level in FPSO crude oil and/or other liquid storage tanks and alarm FPSO operators if the liquid level changes rapidly and the speed of change exceed a preset threshold, for example due to a liquid leak or due to an excessive liquid influx into the FPSO storage tanks, for example due to pressure fluctuations in the FPSO risers and/or associated oil and/or gas production wells.
During severe weather conditions the FPSO unit will make oscillating motions due to wave and/or wind impact, which may induce waves in the FPSO crude oil and/or other liquid storage tanks, which may generate an excessive amount of nuisance alarms of the FPSO surveillance system.
There is a need for an improved FPSO surveillance system, which does not generate an excessive amount of nuisance alarms during severe weather conditions.